Project Summary/Abstract The long-term goal of our research program is to develop the scientific evidence needed to bring competency- based evaluation of surgical skills to orthopedics. The objective of this application is to provide the orthopedic training community with scientifically defendable criteria for critical orthopedic surgical skills at three key developmental points in surgical residency: ready to operate, ready to lead a surgery supervised by faculty, and ready for independent practice. The central hypothesis of this project is that orthopedic surgical skill competence can be objectively, quantitatively, and reliably measured from surgical results that impact patient safety. This hypothesis is based on previous multi-institutional simulation studies conducted with residency programs throughout the Midwest region. The proposed research explores training and assessment programs with several novel surgical simulators. It will also explore ground-breaking analysis techniques for assessing operating room performance from surgical radiographs and from computational, image-based, 3D model reconstruction. This project further expands previous work to more residency programs and to two national ortho- pedic organizations: the Orthopedic Trauma Association, which offers training programs to over a hundred residents sev- eral times a year, and to the American Board of Orthopedic Surgeons, which reviews the credentials and skills of 900 or- thopedic surgeons each year, certifying many to become official diplomates of ABOS. The participation of these national organizations, which provide a large number of potential research participants, creates the opportunity for achieving exciting new research goals, including these three specific aims. Specific Aim 1 is to measure orthopedic trauma surgery skill through surgical results. The working hypothesis for this aim is that sur- gical skill in orthopedic trauma can be measured by analyzing radiographic images associated with a surgery. Specific Aim 2 is to develop simulator-based training programs that improve surgical results. The working hypothesis is that residents who practice key skills until achieving proficiency will perform better in the operating room than residents with- out training. Specific Aim 3 is to define simulator-based assessments that generalize to clinical performance. The working hypothesis is that simulator assessment measurements will discriminate among levels of surgical skill and will also generalize across surgical tasks and between simulation and clinical practice. The proposed research will provide a safe environment for orthopedic surgeons to acquire valuable experience without putting patients at risk. It will also help to establish reliable measures of clinical performance competency and their potential use for credentialing and certification. Finally, as new simulation capabilities become available over the ensuing years, this work will have successfully shown the way from development to changing practice.